Semaphore-signal-operating mechanism



JA C. LINDNER.

SEMAPHORE SIGNAL OPERATING MECHANISM.

APPLlCATION FILED NOV. 26.1917.

Patented J an. 20, 1920.

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UNITED STATES PATENT OFFICE.

JOHN C. LINDNER, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, OF GATES, NEW YORK, A CORPORATION OF NEI/V YORK.

SEMAPHORE-SIGNAL-OPERATING MECHANISM.

Application filed November 26, 1917.

To all whom t may concern: g

Be it known that I, Jol-IN C.`LINDNER, a citizen of the United States, and resident of the city of Rochester', in the county of Monroe and State of New York, have invented a new and useful Semaphore-Signal-Operating Mechanism, of which the following is a specification.

This invention relates to electrically operated semaphore signals used for the control of railway traflic, and more particularly to an improvement for economizing in the energy used for holding said signals in their different operated positions.

The apparatus or mechanism in common use for electrically operating semaphore signals, while diifering to a certain extent in the details of construction, include a device, commonly termed a hold-clear mechanism, which serves to hold the semaphore blade in its one or more operated positions. In the so-called normal clear system of automatic block signaling, in which the semaphore blades of the signals are in a vertical operated position normally, that is, when no train is present in the blocks guarded by the signals, electrical energy must be supplied during the greater part of the time to the holdclear mechanism; and consequently, in this type of signaling, which is very generally used, the eiiiciency and economy of operation of this hold-clearl mechanism constitutes a very important part of the tota-l efficiency and economy of the system.

The hold-clear mechanisms which are commonly used and with which I am familiar, are of the type in which a latch or detent, operated b y an electromagnet, is used to retain the semaphore blade in its operated position. It is a characteristic of this type of' hold-clear mechanism that the energy required to place the mechanism in anI operated condition is greater than that required to retain the mechanism in its operated condition. This characteristic follows from the fact, well known in connection with electromagnets, that the' current flowing in the winding of an electromagnet which is necessary to attract the armature, is greater than the current necessary to hold the armature in its attracted position. In other words, the pick up current of a hold-clear mechanism using an electromag- Specicaton of Letters Patent.

Patented Jan. 20, 1920.

serial No. 203,973.

netis greater than the hold up current. As a result of this characteristic, if a holdclear magnet having a single winding is connected to a battery supplying a substantially constant voltage, there will be an excess current owing after the armature of the hold-clear magnet has been attracted. To obviate this excess current, which is unnecessary for successful operation and is merely wasted, it has been proposed to make provision for automatically increasing the resistance of the circuit of the hold-clear magnet after it has attracted its armature, so as to reduce the current flowing through the windings thereof to an amount more nearly in accord with the amount necessary to retain its armature in its attracted position, thereby dispensing' with the excess and wasted current. In order that the currentflowing through this added resistance may perform some useful work, it is generally contemplated to make this added resistance a part of the winding of the holdclear magnet. F or example, in one type of hold-clear mechanism with which I am familiar, the hold-clear magnet is provided with two separate windings, and automatic devices are provided to connect the battery to one winding to pick up the armature of the hold-clear magnet, and then, after the arma-ture has been picked up, to connect t-he two windings in series. The provision of two windings in the hold-clear magnet does not lend itself to the eliicient utilization of winding space, and although such a construction compensates to a certain extentfor the different values of the pick up current and the hold up current, the economy and efficiency of the hold-clear magnet as a whole is reduced.

There is another factor entering into the question of the eliciency and economy of the hold-clear mechanism, and that is the variation in the voltage of the battery used for supplying current to the hold-clear magnet. In the signaling systems with which I am familiar, the battery used for suppl 1- ing current to the hold-clear magnet is the same one used for supplying current to the operating motor; and due to the comparatively high average current demand on the battery, there is in practice a considerable decrease in the voltage of the battery during its active life. It is evident that it is necessary to design the hold-clear magnet so that it will operate on the minimum voltage contemplated, otherwise, when the battery is nearly run down or exhausted, the hold-clear mechanism will fail to operate; and when the hold-clear magnet is designed to satisfy this condition, it is evident that there is an excess of current flowing whenever the battery is supplying a voltage greater than this minimum, as would be very appreciably true when the battery is new or has just been renewed. For this reason, disregarding the eiiiciency of the hold-clear magnet, there is a waste of energyl depending upon the extent of variation in the voltage of the battery from its maximum to its minimum during its life.

Vith the above considerations in mind, one of the principal objectsof this invention is to devise an improved construction and arrangement of parts and circuits, in a semaphore signal operating mechanism, so as 'to decrease the energy consumption of the hold-clear mechanism, thereby economizing in battery power and reducing the cost of operating the signaling system.

A further object of the invention is to devise a semaphore signal operating mechanism of a more efficient type which is constructed in accordance with the principles which have been found by trial in actual practice to be safe and reliable.

A still further object of the invention is to simplify the construction of semaphore signal operating mechanisms in general.

Further objects and advantages will appear as the description of the invention progresses and the novel features of the invention will be particularly pointed out in the appended claims.

Tn describing the invention in detail reference is made to the accompanying drawing wherein is illustrated a preferred physical embodiment of the invention, and wherein like characters of reference designate corresponding parts throughout the several views, and in which:

Figure 1 is a diagrammatic view partly in the nature of a wiring diagram, which shows the parts and electrical connections of a device constituting one .embodiment of the invention, said parts being illustrated more with a view of making their functions and operations clearly understood than with regard to their exact construction and arrangement; Fig. 2 is a diagrammatic representation showing how the contacts of the circuit controller are operated during the movement of the semaphore .blade from its horizontal or Zero degree position to its vertical or ninety degree position.

Referring to Fig. 1 of the drawing, the invention is shown as applied to a well known type of semaphore signal operating mechanism, such as shown and described in the patent numbered 1,056,992 granted to VJ. K. Howe March 25, 1913. This type of semaphore signal operating mechanism comprises a semaphore shaft 1 to which a semaphore blade D is connected, said semaphore blade D being moved to different operated positions so as to give the desired signal indications. The shaft 1 is biased to rotate in a clockwise direction, as viewed in Fig. 1, by the torque exerted by the weight of the semaphore blade D g and is turned to move the semaphore blade D to its operated positions by an electric motor B, which may be of any suitable construction. This motor B is illustrated in a conventional way and comprises an armature 2 and a field 3, the shaft l of the armature 2 being connected tothe main shaft 1 by suitable gearing C, as shown in Fig. 1.

A toothed wheel 5 is mounted on the armature shaft 4 by a friction clutch, one suitable form of clutch being fully shown and described in patent numbered 1,077,136 granted to F. N. Hall October 2S, 1913. This clutch prevents severe shocks to the motor B and the other moving parts of the mechanism when said wheel 5 is stopped by the hold-clear mechanism A. This holdclear 4mechanism A, as shown, comprises a swinging arm 6 pivotally supported at its upper end to a fixed member 7 which in practice is a. part of the motor casing (not shown). This swinging arm 6 carries a pivoted pawl or detent 8 which is pulled by a spring 9 in one direction against a stop pin 10. The detent S is provided with two teeth at its outer or free end; and the arm 6 is positioned with reference to the wheel 5. so that when the lower end of the swinging arm 6 is moved inwardly or toward the wheel 5, the teeth on the detent 8 will mesh with the teeth on the wheel 5. The lower end of the swinging arm 6 has a slot formed therein, in which fits a pin 11 carried by the upstanding shorter arm of an angle lever 12. The angle lever 12 is pivotally supported by a pin to a fixed member 13 which in practice is a part of the motor casing (not shown). Suitable means is provided to limit the downward movement of the longer arm of the angle lever 12; and for simplicity this means is shown as a fixed pin 14. The angle lever 12 has fastened thereto an armature 15 of an electromagnet F conveniently termed the hold-clear magnet, which is fastened to a suitable part of the frame of the mechanism.

The operation of the hold-clear mechanism A is as follows: When the hold-clear magnet F is energized and its armature 15 is attracted, the angle lever 12 is rocked on its pivot pin, and the lower end of the swinging arm 6 is forced inwardly toward the wheel 5 by the pin 11 carried by the shorter arm of the angle lever 12, thereby causing the teeth of the detent S to engage with the teeth on the wheel 5. When the wheel 5 is rotated in a counterclockwise direction, as is the case when the semaphore blade D is moved from its zero degree position to either of its operated positions, the detent 8 is pushed downward out of the way of the teeth on the wheel 5, this being allowed by the spring 9 attached to said detent. However, when said wheel 5 is rotated in a clockwise direction, as is the case when the semaphore blade D moves in response to its bias, the teeth on the detent 8 will engage with the teeth on the wheel 5, and the detent 8 being carried upward by the wheel 5 against the stop pin 10, the wheel 5 is locked against clockwise rotation, and subject to the slipping of the friction clutch prevents further movement of the armature shaft 5 by the weight of the semaphore blade D. `When the coils of the hold-clear magnet F are denergized, the armature 15 and the angle lever 12 drop by their own weight until the angle lever 12 engages its stop pin 14. The lower end of the swinging arm 6 is, therefore, forced to the left, as viewed in the drawing, and the detent 8 moved out of engagement with the teeth on the wheel 5, thereby releasing the wheel 5 and allowing the semaphore to gravitate toward its biased or zero degree position. A further detail eX- planation of the construction and operation of this hold-clear mechanism may be found 'by reference to the patent numbered 1,077,136, hereinbefore referred to, which discloses practically the same construction, except that in the hold-clear magnet F herein shown and described there is only one coil or winding on each core.

The semaphore shaft 1 of the signal operating mechanism is operatively connected by a pair of segmental gears 16 and 17 to a shaft 18 of a suitable circuit controller E, said shaft 1S being parallel to the semaphore shaft 1. This circuit controller E comprises a drum 19 constructed of any suitable insulating material, such as wood, which is secured to the shaft 1S by screws. Associated with this drum 19 are a number of contact groups a, b, c and d, each of said groups consisting of a pair of contact springs and a contact strip on the drum 19. The contact springs are carried by bars 2O of suitable insulating material which in practice are supported in any suitable manner by the framework (not shown) of the circuit controller E; and the contact strips on the drum 19 are made of the appropriate length and are so positioned on the drum as to connect the respective pairs of contact springs in the desired positions of circuit controller E, thereby completing metallic electrically conducting paths through said pairs of contact springs.

A device commonly known as a snubbing device, and represented generally on the drawing by the letter G, is also provided. This snubbing device acts to form a low resistance shunt or short circuit around the field and armature of the operating motor B at predetermined points during the travel of the semaphore blade D in response to its bias, from its ninety degree position to its forty-five degree position and also to its Zero degree position, so that the motor will act as a generator and provide an electrical brake or dashpot for said semaphore blade D. As shown in Fig. 1 of the drawing, the snubbing device G comprises a supporting arm 21 secured at its lower end in any convenient manner to an insulating member 22, said member in practice being secured to the framework (not shown) of the mechanism. A resilient contact finger 23 is secured at its lower end to the supporting' arm 21 and at its upper end engages with certain fixed contacts represented on the drawing by arrows, when said Contact finger is in its extreme positions. A dog 21 is pivotally supported at the upper end of the supporting arm 21, said dog 21 being provided with a pin 25 which bears against one face of the contact finger 23; and at the outer end of the dog 21 is another pin on which is mounted a roller 26. 'A member 27 provided with two lugs or projections 2S and 29 separately spaced thereon, is secured to the drum 19 and adapted to move therewith, the lugs 2S and 29 being' positioned so as to strike the roller 26 when the drum 19 is rotated.

`Since the snubbing device G has no particular bearing upon the invention herein shown and described a brief description will be sufficient for a clear understanding of the present invention, a more ldetail description of the construction and operation of the snubbing device being given in the patent numbered 1,092,266 granted to WT. K. Howe, April 7, 1914.

The contact finger 23 tends to assume the left hand extreme position, as shown; and when the drum 19 of the circuit controller E is rotated in the clockwise direction, as is the case when the semaphore blade D moves from its horizontal or zero degree position toward its vertical vor ninety degree position, the projections 2S and 29 tilt up the dog 24 without altering the position of the contact finger 28. However, when the drum 19 moves in a counterclockwise direction, as it does when the semaphore blade D moves in response to its bias, the projections 2S and 29 on the member 27 successively engage the roller 26 and cause the contact finger 23 to move to the right, breaking contact with one of its cooperating contacts and making contact with the other. As soon as each ot said projections have passed the roller 26 the contact linger 23, due to its resiliency, will return to its normal position, as shown. The parts are preferably arranged so that the movement ot the contact linger 23 will take place when the semaphore blade D assumes an angle in its downward movement ot approximately 75 and continues until said semaphore blade D has reached an angle ot' approximately 55, whereupon the dog 26 will be released and the contact finger 23 will assume its normal position, as shown in the drawing. A similar action takes place when the semaphore blade D moves trom its #150 position to its OO position, except that in this case the dog` 26 is engaged by the projection 29 on the member 2T instead of the projection 28, and the Contact linger 23 is moved when the semaphore blade D assumes an angle of approximately 300 and remains in its moved position until said blade has reached an angle in its downward movement of approximately 100. The points in the movement et the semaphore blade at which the semaphore contacts are closed is indicated diagrammatically in Fig. 2.

Each time the contact linger 23 is moved to close the snubbing contacts, a short circuit is formed tor snubbing the motor B, so as to prevent sudden shocks or jars to the mechanism when the semaphore blade D is stopped in it-s different indicating aositions, said short circuit being traced as follows: from one side et the armature 2 ot' the motor B, ield 3 of said motor, conductor 30, arm 21 and contact linger 23 ot the snubbing device G, conductor 31, resistance coil 32, conductors 33 and 34 back to the other side of the armature 2 of the motor B.

Two sources of electrical energy are used for supplying the energy necessary to perform the various functions of the devices embodying' this invention. One et these sources consists of a high voltage battery J, such as 16 cells; and the other ot said sources consists of a low voltage battery l, such as 2 cells. According to the particular einbodimentof the invention illustrated, the battery J as will be hereinafter more fully explained, is used tor supplying energy to the motor B to operate the semaphore blade D to its ditterent operated positions; both of the batteries J and K connect-ed in series are used for supplying energy to pick up the armature ot the hold-clear magnet F; and the battery K is used alone for supplying current to the hold-clear magnet F to hold its armature in its picked up position.

In the particular embodiment ot the invention illustrated, the semaphore signal operating mechanism is controlled by a polarized control or line relay I-l, which is provided with two neutral contact fingers and 36, and two polar Contact fingers 37 and 38. rlhis particular type oit' relay has been selected as illustrative oit the means for controlling the circuits; but it is to be understood that other types ot relays, separate home and distant relays, or other forms ot automatic or manually operated controlling devices, might be employed equally as well. The construction and operation ot' polarized relays, such as the relay H, are well known to those skilled in the art, and it is considered sutlicient to merely point out that, when current liows through coils 39 of the relay H in one direct-ion, the polar cont-act fingers 371 and 38 stand in the normal position shown in the drawing, and that, when current flows through said coil 39 in an opposite direction, the lower ends ot these polar Contact fingers move to the lett to reverse position. Then current is flowing in either direct-ion in said coils 39, the neutral contact lingers and 36 are in the raised position, as shown; but when no current flows in the coils 39, the neutral contact fingers: 35 and 3G will drop, andthe polar contact tinge-rs 37 and 38 will assume a middle or vertical position.

The wires which connect the different operating parts will not be described in detail since the electrical connections of the di'erent parts will be pointed out during the tollowing description ol the operation.

Operation: The semaphore signal ope-rating mechanism hereinbeiore described is designed to turn the shat't 1 and the semaphore.'

blade D from its biased position or the zero degree position to either the forty-tive degree position or the ninety degree position, and also to hold said shaft 1 in either one oit these operated positions. These movements are caused to occur by interrupting the current or changing its direction of flow in the control relay H. ln block signal systems with which l am familiar, it is the usual practice to cause the semaphore blade. of the signal guarding a block or tract seotion to drop to. its zero degree or stop position when a train enters that particular block or track section. This is accomplished by short circuiting the track relay through which said signal is controlled; which acts to interrupt the supply ot current to the corresponding control or line relay H. lhen said train has passed out of that block and into the block next in advance, current is again supplied to the relay H, flowing in such direction as to move its polar contact lingers t0 the reverse position, and the signal then automatically assumes its or caution position. 7When the train continues on its way and passes into the second block in advance, the direction of the flow of current in the relay H is reversed so as to shift its polar contact fingers to the normal position (shown in Fig. 1), whereupon the semaphore blade of said signal will assume its 90o or clear position.

Taking up these steps in the complete operation in order, assume that the semaphore blade D is in its 90o or clear position as: shown, there eXists a circuit, which is conveniently termed the 90O holding circuit, forI energizing the coils of the hold-clear magnet F so as to hold the semaphore blade in its 90C or clear position, this circuit being traced as follows: commencing at one side of the battery K, conductor 40, neutral contact finger 36 of the cont-rol relay H in itsi upper position, conductor 41, polar contact finger 38 of said relay in its normal position, conductor 42, contact group a of the circuit controller E, conductors 43 and 44, the hold-clear magnet F, conductors 45 and 46, contact finger 23 and supportingarm 21 of the snubbing device G, conductor 30, field 3 and armature 2 of the motor B, conductors 34 and 47, neutral contact linger 35, conductors 48 and 49 back to the other side of the battery K.

The circuit just traced supplies current to the coils of hold-clear magnet F sufficient to hold its armature l5 in its attracted position, so as to hold the detent 8 of the holdclear A in engagement with the teeth of the wheel 5 on the armature shaft 4, thereby holding` the semaphore blade D in its 90o or clear position.

The semaphore blade is caused to change from its 90o or clear position to its zero degree or stop position when current is cut off' from the coils 39 of the control relay H, which in practice results from the dropping of the track relay of` the track section as sumed to be governed by the signal. This causes the contact fingers 35 and 36 of the relay H to drop, thereby interrupting not only the 90o holding circuit already traced but also all of the operating and holding circuits for said signal which will be traced hereinafter. The semaphore blade D now moves in response to its bias to its zero degree or stop position. In practice the semaphore blade is arrested in its zero degree or stop position by a stop of suitable construetion, such as that shown and described in the patent numbered 1,137,323 granted to W. K. Howe, April 27, 1915; but for simplicity this stop is diagrammatically illustrated as a xed pin 50. The snubbing device Gr will act to cause the movement of the semaphore blade D to be slowed down just before it reaches its 45O position and also just before it reaches its 0O position, in the way already explained, thereby avoiding suddenv shocks or jars to the motor and the mechanism.

:Referring to the operation of moving the semaphore blade from its 00 or stop positior to its 45o or caution position, energy is ap plied to the coils 39 of the control relay H and in a direction which causes the polar contacts 37 and 3S of said relay H to assume the reverse position, shown inl Fig. 1 by dotted lilies. The contact fingers 35 and 36 are picked up and the polar contact fingers 37 and 38 are moved to the reverse position. With the parts in the condition as stated, a circuit for energizing the operating motor B, which will hereinafter be termed the 45o operating circuit, is established, said circuit being traced as follows: commencing at one side of the battery J conductors 51 and 48, contact finger 35, conductors 47 and 34, armature 2 and field 3, conductor 30, contact finger 23, conductors 46, 52 and 53, contact group d, and conductors 54 and 55 back to the other side of the battery J.

The motor B being supplied with current by the circuit just traced will move the semaphore blade D counterclockwise toward its operated positions. The drum 19 of the circuit controller E which is secured to the shaft 18 will be rotated therewith in a clockwise direction and will thereby cause the contact strips on said drum to be brought into and out of contact with their respective Contact springs. Fig. 2 shows diagrammatically the points in the movement of the semaphore blade at which a conducting path is made through each contact group. Referring to Fig. 2, the contact group fl, included in the 45o operating circuit, remains closed until just before the semaphore blade D reaches its forty-five degree or caution position; and just before the contact strip of the group Z breaks contact with its coperating contact springs, the contacts of group Z) are closed, whereupon a circuit for energizing the coils of the hold-clear magnet F is established, said circuit, hereinafter termed the 45c pickup circuit, being traced as follows: conmiencing at one side of the battery K, conductor 40, contact finger 36, conductor 56, contact group Z), conductors 57 and 44, hold-clear magnet F, conductors 45, 52 and 53, contact group ci, conductors 54 and 55, battery J, and conductors 51 and 49 back to the other side of the battery K.

This 45O pickup circuit last traced includes the two batteries J and K in series so that sufficient current can be supplied to the hold-clear magnet F to attract its armature 15 from its lower' position. The attraction of the armature 15 moves the detent 8 inwardly toward the toothed wheel 5, but since the motor is still being supplied with current, the armature shaft 4 is rotating in a counterclockwise direction, and the detent 8 ratchets idly over the teeth of the wheel 5. Vhen the 45O operating circ-uit is interrupted at the contact group d which interruption occurs just before the signal reaches its 45O position, there is established a circuit, hereinafter termed the 45 holding circuit, which may be traced as follows: commencing at one side of the battery K, conductor 40, contact finger 36, conductor 56, contact group b, conductors 57 and 44, hold-clear magnet F, conductors 45 and 46, contact finger 23, conductor 30, field 3 and armature 2, conductors 34 and 47, lcontact nger 35, and conductors 48 and 49 back to the other side of the battery K.

`When the supply of current to the opere ating motor is cut olf, the semaphore blade D continues to move through a small angle toward its 450 position due to the momentum of the motor armature, the gears and other moving parts, the detent 8 of the holdclear mechanism A continuing to ratchet idly over the teeth of the wheel 5; but as soon as the semaphore blade D comes to rest at about its 45o position and commences to settle back toward its biased position, the detent 8 is carried by the teeth of the wheel 5 up against the stop 10 and acts to lock the Wheel 5 against clockwise rotation, thereby holding the semaphore blade in its 45O position.

The next movement of the semaphore blade D from its 45O or caution position to its 90o or clear position is accomplished by reversing the polarity of the circuit controlling the polarized relay H.

When the direction of the flow of current through the coils 39 of the control relay H is thus changed by a change in the polarity of its controlling circuit, the neutral contact fingers 35 and 36 momentarily drop, for reasons apparent to those skilled in the art; and it is found that this temporary interruption of the 45 holding circuit denergizes the coils of the hold-clear magnet F suiiiciently to allow the armature to drop.

As soon as the neutral contact fingers and 36 return to their upper position after momentarily dropping, the holding circuit hereinbefore traced is restablished, but since this circuit onl includes the low voltage batter. K and since the armature 15 of the hold-clear magnet F is now in its lower position, the current flowing in this 45 holding circuit is not suflicient to cause the armature 15 to be again attracted. The operation just described merely results from the operating characteristics of the polarized relay H and is not essential or of great importance in the operation of the mechanism as a whole, since the only effect is to obviate the ratcheting of the detent 8 over the teeth of the wheel 5 during the first part of the movement of the semaphore blade toward its 90O position, that is, until the 45 holding circuit is broken by the opening of the contacts of the group b.,

The reversal of the polarity of the con trolling circuit for the relay H causes the polar contact fingers to shift to their normal position (shown in full lines on the drawing), whereupon a circuit for supplying energy from the battery J to the motor B is `established. This circuit is termed the 90o operating circuit and may be traced as follows: commencing at one side of the battery J, conductors 51 and 48, neutral contact finger 35, conductors 47 and 34, armature 2 and field 3, conductor 30, contact finger 23, conductors 46, 52 and 58, contact group c, conductor 59, polar contact finger 37, and conductors and 55 back to the other side of the battery J.

Just before the semaphore blade D reaches its 90 or clear position a circuit is established, which is analogous to the 45 pickup circuit and which energizes the coils of the hold-clear magnet F sufficient to pick up its armature 15. This circuit is termed the 90o pickup circuit and may be traced as follows: commencing at one side of the battery K, conductor 40, neutral contact finger 36, conductor 41, polar contact finger 38, conductor 42, contact group a, conductors 43 and 4-4, hold-clear magnet F, conductors 45, 52 and 58, Contact group c, conductor 59, polar contact finger 37, conductors 60 and 55, battery J, and conductors 51 and 49 back to the other side of the battery K.

Just before the semaphore blade D reaches its 90o position (approximately 88), the contacts of the group c open and break the 90O operating circuit, the contacts of the group a, however, remaining closed. Current then flows in a circuit termed the 90O holding circuit, which may be traced as follows: commencing at one side of the battery K, conductor 40, neutral contact finger 36, conductor 41, polar contact finger 38, conductor 42, contact group a., conductorsl 43 and 44, hold-clear magnet F, conductors 45 and 46, contact finger 23, conductor 30, field 3 and armature 2, conductors 34 and 47, neutral contact finger 35, and conductors 48 and 49 back to the other side of the battery K.

' ln block signaling systems of` the more common type with which l am familiar, a semaphore blade is normally in its 90 or clear position; and the usual movements of this blade are from its 900 position to its 00 position, then from its Oo position to its 450 position and from its 450 position to its 90 position. @cca-sionally under special conditions it becomes necessary for the semaphore blade to more from its 90 position to its 45 position, and although this movement is generally of rare occurrence, it is necessary to construct the operating mechanism so that this movement may be accomplished 'if necessary, One illustration of the special conditions resulting in this movement of the semaphore blade from its 90D position to its 45 position, is when a train makes a backup movement from one block into the neXt block in the rear. When such a backup movement occurs the polarity of current flowing in the relay H of the second signal in the rear is reversed to move its neutral contact fingers from the normal position to the reverse position. Remembering that the semaphore blade in question is in its 900 or clear position, with the associated parts as shown in the drawing, when the polar contact ringer 38 moves to its reverse position it interrupts the 900 holding circuit, thereby releasing the hold clear mechanism. The movement of polar contact finger 37 breaks the 90o operating circuit. Consequently, semaphore blade D moves in response to its bias to-ward its 450 position. At the appropriate point in the movement of the semaphore blade the snubbing device G is operated, as hereinbefore explained, to break or retard movement of the semaphore blade. Just before the semaphore blade reaches its 45 position the contacts of the group b close and establish the 45 holding circuit, but since this circuit includes only the low voltage battery K, the current flowing is not suiiicient to attract the armature l of the hold clear magnet F. When the semaphore blade has moved to a position a few degrees below its 450 position, the contacts of the group Z are closed and establish the 450 operating circuit which supplies current to the motor tending to drive the semaphore blade B back toward its 90o position. The contacts of the groups and Z being both closed, the pickup circuit is also established, and the armature l5 of the hold clear magnet F is attracted. The application of current to the operating motor quickly brings the semaphore blade to a stop and commences to move the blade back towardits 450 position, and when the blade h as been moved back to the point where the contacts of the group d open and interrupt the 45o operating circuit, the 45 holding circuit is established, and the semaphore blade is held in its 4:50 position.

From a consideration of the construction and operation of the embodiment of the invention hereinbefore described, it can be seen that, in accordance with this invention, two batteries are used for supplying current to the semaphore signal operating mechanism, one of these batteries having a comparatively high voltage and the other a comparatively low voltage. Furthermore, it can be seen that the current for the operating motor is supplied from the high voltage battery alone, the pickup current for picking up the armature of the hold-clear magnet is suppliedk from lthe two batteries in series,

and the hold up current for holding up the armature of the hold-clear magnet is supplied from the low voltage battery. By providing these two batteries with different voltages and by providing automatic means for connecting the batteries to the operating motor and the hold-clear magnet, as described, the eiiciency and economy of operation or' the hold-clear mechanism is much improved.

In the first place, the hold-clear magnet is provided with a single winding, and consequently, a more eilicient and economical distribution of the copper in the winding space may be obtained than in the case where two windings are used, the desired values of the pick up and hold up current for economical operation being obtained by varying' the voltage applied to this single winding.

A still further advantage follows from the fact that the hold up current supplied to the hold-clear magnet, is derived from a low voltage battery which is used for this purpose only. It is a well known characteristic of primary cells, such as are commonly used in railway signaling systems, that the variation in voltage during the active life oi the cell depends to a large eX- tent on the average rate of discharge. With a high rate oi' discharge the voltage drops through a greater range before the cell is exhausted than with a low rate of discharge. Vhen the hold-clear magnet is operated by current supplied from the `same battery used for operating the signal, the average rate of discharge of this battery is much higher than when the hold-clear magnet is operated by current derived from a battery used for this purpose alone. This difference will be readily understood when it is appreciated that the amount of current which it is necessary to supply to the hold-clear magnet to retain its armature in the attracted position is very small, being in some cases as low as .019 ampere, while the operating current for the motor is much higher, being in some cases 2.50 amperes, so that the rate of discharge of a battery used solely for the purpose of supplying the hold up current to the hold-clear mechanism, is so small that the drop in voltage during the active life of the battery is slight. As pointed out hereinbefore, the hold-clear magnet must be designed so as to hold itsarmature in the attracted position upon the minimum voltage of the battery, that is, the voltage existing when the cell 1s nearly exhausted and 1n condition to be renewed; and consequently,

since in this invention the low voltage battery is used orqsupplying hold up current for the hold-clear magnet only, so that the average .voltage oi' the battery during its active irte corresponds very closely to the minimum voltage, it is apparent that there is a very much less waste ofenergy in eX- cess current used.

Another feature of economy in a semaphore signal operating mechanism embodying the invention results from the fact that the hold up current or the hold clear mechanism is supplied from a separate battery which is not used for operating the signal. It is well known that when current is taken from a primary cell, particularly such an amount of current as is necessary to operate the motor in a semaphore signal operating mechanism, there is a considerable voltage drop due to the internal resistance of the cell and due to the chemical action, usually polarization, which takes place, so that after a comparatively large current has been taken from a battery of primary cells for the purpose of operating the semaphore, the Voltage available from this battery for operating the hold-clear mechanism is temporarily lower than the voltage which this battery is capable or' giving. Since it is necessary for satisfactory operation to design the hold-clear magnet so that it will operate upon this minimum voltage, even though it exists only temporarily, there is an excess and waste current flowing when the battery has recovered and is supplying its normal voltage. According to this invention, the disadvantage last explained is obviated by reason of the fact that the hold up current for the hold-clear magnet is taken from the low voltage battery which has not had any current taken from it for operating purposes. While it is true that in accordance with this invention the battery used for operating the signal is also used for supplying the pick up current for the hold-clear mechanism, no serious difficulty results by reason of the fact that the voltage of the operating batter being determined with regard to the energy needed to operate the signal, is amply sufficient to supply the pickup current, even though it has just been used for supplyingcurrent to operate the motor. Furthermore, for simplicity in the arrangement of circuits and controlling devices, the low voltage battery primarily used for supplying hold up current for the hold-clear magnet, is 'connected in series with the high voltage operating battery to supply the pickup current for the hold clear mechanism, so that regardless of the temporary voltage drop oli the operating battery, there is ample voltage to supply the necessary pickup current.

It should also be noted that the advantages associated with this invention do not require any additional or complicated apparatus, the necessary change in the circuit connections being made in a simple and reliable manner by the circuit controller of the signal operating mechanism,

While I have illustrated and described my invention in connection with a particular type of semaphore signal operating mechanism, together with a polarized relay for controlling this mechanism, it should be understood that my invention is susceptible of use in connection with various types of signal operating mechanisms and various types of controlling devices. A lso, it is apparent that various changes and modications may be made in the particular embodiment of the invention illustrated and described without departing from the fundamental combination of elements and functions delined in the appended claims and constituting the invention.

What I claim as new and desire to secure by etters Patent of the United States, is:

1. In a semaphore signal operating mechanism, the combination with an operating motor and a hold clear magnet, of two primary batteries of different voltages, and means including circuit controllers operated in accordance with the movement of the semaphore blade for establishing an operating circuit for the motor including` the high voltage battery and for establishing successively in overlapping sequence circuits for the hold clear magnet including first the two batteries in series and then the low voltage battery.

2. In a semaphore signal operating mechanism having an operating motor and a hold clear magnet, the combination with two sources of electrical energy of dierent voltages, of means including circuits and controlling devices automatically controlled in accordance with the movement of the semaphore blade for causing the high voltage battery to supply current for operating the motor, the two sources in series to supply current for initially energizing the hold clear magnet, and the low yvoltage source to supply current for maintaining the energization of the hold clear'magnet.

3. In a semaphore signal operating mechanism, the combination with an operating motor and a hold clear magnet, of two primary batteries of dierent voltages, a first circuit including` the high voltage battery for supplying operating current to theA motor, a second circuit including two batteries in series for supplying current to pick up the armature of the hold clear magnet, a third circuit including the low voltage battery for supplying current to hold up the armature of the hold clear magnet, and circuit controlling means operated in accordance with the movement of the semaphore blade for interrupting the irst circuit and establishing the second and third circuits in overlapping sequence when the semaphore blade reaches an operated position.

4f. In a semaphore signal operating mechanism comprising operating motor hold clear magnet, the combination with a circ-uit including the source or" 4energy for supplying current to the operating motor, of a second circuit including a separate source of energy for supplying current to the hold clear magnet, and means operated automatimilly in accordance with the movement of the semaphore blade for establishing said circuits successively.

5. In a semaphore signal operating` mechanism having` an operating motor and a hold clear magnet, the combination with a high voltage battery suitable for supplying operating current to the. motor, a low vvoltage battery capable of supplying suflicient current to maintain the armature of the hold clear magnet in its attracted position, and controlling circuits and apparatus operated automatically in accordance with the movement of' the semaphore blade for causing an electrical connection between the high voltage battery and the operating motor during the movement of the semaphore blade to an operated position and for causing an electrical connection between the low voltage battery and the hold clear magnet after the semaphore blade has reached said operated position.

6. In a semaphore signal operating mechanism comprising an operating motor and a hold clear magnet, the combination with two sources of energy ot different voltages, of a circuit including the high voltage source for supplying current to the operating motor, a secondcircuit including both sources in series for supplying current sufii cient to cause attraction of the armature ot the hold-clear magnet, a third circuit simultaneously established with said second circuit and including the low voltage source of energy alone :for supplying sufficient current to maintain the armature of the hold-clear magnet in its attracted position, and means operated automatically in accordance with the movement of the semaphore blade for rendering said circuits successively effective in overlapping sequence.

In a semaphore signal operating mechanism, the combination with an operating motor and the electro-magnet of a holdclear mechanism, of two sources of electrical energy of different voltages, an operating circuit for the motor including the high voltage source, and two other circuits governed in accordance with the movement of the semaphore blade for successively connecting in overlapping sequence the electromagnet of the hold-clear to the two sources in series and then to the low voltage source.

8. In a semaphore signal operating mechanism, the combination with an operating motor and a holdclear magnet, of two primary batteries of different voltages, a first circuit including the high voltage battery 'for supplying operating current to the motor, a second circuit including two batteries in series for supplying current to ypick up the armature ot the hold-clear magnet, a third circuit including the low voltage battery, the hold-clear magnet and the field and armature ot' the motor, and means operated in accordance with the movement ot' thc semaphore blade acting to establish the three circuits simultaneously during the movement of the blade to an operated position and to interrupt the first and second circuits when the semaphore blade reaches the operated position.

Q. In a semaphore signal operating mechanism of the type in which a semaphore blade is biased for movement in one direction and is operated to different indicating positions by an electric motor and in which the circuits and controlling devices are automatically controlled in accordance with the movement of the semaphore blade, the combination with a hold-clear magnet having single wound coils for holding said semaphore blade in its operated positions, and two sources of electrical energy of dierent voltages, one ot' said sources being used to supply energy of high voltage for operating the motor, two of' said sources connected in series being used f'or supplying energy to pick up the armature of the hold-clear magnet, and the low voltage source being used orsupplying energy to hold up the armature of the hold-clear magnet.

l0. In a semaphore signal operating mechanism, the combination with an operating motor and a hold-clear magnet, of two primary batteries of different voltages, two circuit controllers operated automatically in accordance with the movement of the semaphore blade, the first circuit controller being closed during the movement of the blade nearly to its operated position, the second circuit controller being closed simultaneously with and subsequent to the opening ot' the first circuit controller in the operated position of the semaphore blade, an operating circuit for the motor including the high voltage battery and the first circuit controller, a pickup circuit for the hold-clear magnet including in series the two batteries and the two circuit controllers, and a holding circuit for the hold-clear magnet including the low voltage battery, the motor, and the second circuit controller.

ll. In a semaphore signal operating mechanism, including a hold-clear magnet, the combination with sources of current of dierent voltages, a circuit including a high voltage source and a hold-clear magnet, another circuit including a low voltage source and the hold-clear magnet, and means including circuit controllers operated in accordance with the movement of the semaphore blade :for establishing said circuits in overlapping sequence in the OICleI named When the semaphore blade reaches an operated position.

12. In a semaphore signal operating mechanism, the combination with an operating motoi` and a hold-clear magnet, ofhigh and low Voltage sources of current, circuit controlling means operated in accordance With the movement of the semaphore blade for controlling the connection between said high Voltage source or' current and said op- @rating motor, and means for successively connecting the hold-clear magnet in circuit first With the high voltage source and thenwith the low voltage source alone, as the semaphore blade reaches an operated position7 whereby the different Values of current required to pick up and hold up the hold-clear magnet are automatically obtained.

JOHN C. LINDNER. 

